The independent research and development has been carried out by Baotou Steel based on the technical requirements of hot rolled coil with high strength and corrosion resistance for railway carriages. The mechanical properties and corrosion resistance of the test steel all meet technical requirements through adopting the system of low carbon+copper chromium nickel alloy and appropriate controlled rolling and controlled cooling processes. The trial production results showed that its yield strength was 550~580 MPa, tensile strength was 645~690 MPa, elongation after fracture was 20.0%~22.0%, low-temperature impact absorbing energy at -40 ℃ was 202~255 J and microstructure at room temperature was ferrite+pearlite+bainite, which was with excellent matching of strength and toughness. Its average corrosion rate is 2.813 5 mm/a, while that of Q235B is 36.060 5 mm/a, so its corrosion rate is 7.8% of that of Q235B.

In the paper, the relations between such factors as the microstructure of rails, inclusions, excessive hydrogen and residual stress and Crack Length-Cycle curve are analyzed through the data and diagrams obtained by the tests based on the test of threshold value of crack expansion ΔK_th for U71Mn, U75V and U20Mn quenched rails as well as U75V test steel with the rare earth, lanthanum and cerium. Moreover, the effects of adding the rare earth, lanthanum alloy and cerium alloy into rails on crack growth of rails are analyzed, which could provide new means for analyzing the performances of rails and prolonging service life of rails.

The cracking sample of flash welded wheel steel 380CL for rim is detected and analyzed with optical microscope and microhardness tester. The results showed that the content of C in wheel steel 380CL exceeded the upper limit of internal control, heat with high temperature in the weld region during flash welding was fast, cooling speed was fast after weld, hardenability of weld region was improved and coarse bainite structure appeared; the microhardness of matrix and heat affected zone (HV0.1) was 303~310, while that of weld region (HV0.1) was 346, which was 12%~14% higher than that of matrix and heat affected zone, so the hardness difference was greater and ability of deformation coordination of each structure was poor when the rim flared and deformed so that they were cracked at the junction of weld seam and coarse grain heat affected zone. The weld microstructure could be refined, hardness difference of weld, matrix and heat affected zone could be reduced by strictly controlling the chemical compositions of wheel steel 380CL and reducing welding heat input so that good plasticity of weld could be ensured and cracking rate of forming for rim could be reduced.

The sulfuric acid corrosion resistant steel for railway carriages is with the composition design of low C containing Cr. It is with good comprehensive properties as well as its microstructure is ferrite, bainite and a small quantity of pearlite through the reasonable controlled rolling and controlled cooling process, which could meet the requirements of steel for railway carriages. The scanning electron microscope observation showed that Cu, Cr, Ni and Si were obviously enriched at the interface between oxide layer and matrix of steel. As a result, the adhesive force of oxide layer and matrix is increased to prevent permeation of anions so that the resistance to corrosion of steel surface is enhanced. The corrosion rate of the test steel in the immersion test of 20% sulfuric acid is 6.46 g/(m²·h), which is 20.59% of that of Q355B, so its resistance to sulfuric acid corrosion is excellent.

In the article, the loader and unloader as well as process flow of walking beam cooler for wide and thick plate are introduced. The production status is that there is scuffing of plate during the lateral moving process of plate in walking beam cooler of production line of wide and thick plate in CSP Plant of Baotou Steel as well as plates are seriously skewed when lateral moving to the exit position so that unloading of plate cannot be carried out. The reason is the equipment wear of walking beam cooler in long-term use through analyzing, resulting in slight differences of each step of lateral moving in the two zones of cooling bed so that the cumulative deviations during the whole lateral moving process are too large. As a result, the plates are skewed in lateral moving process. The solution of compensating slight differences of each step of lateral moving in the two zones of cooling bed by adding the absolute value encoder and revision program is proposed.

In order to improve the engineering construction quality and promote the construction efficiency of building engineering, construction teams need to reasonably apply digital technologies in engineering management process to meet the requirements of current era for engineering management. The feasible application strategies for digital technologies in engineering management could be formulated by analyzing the specific application values of digital management methods and application characteristics of digital technologies to promote effective reform and improvement of construction management, which makes the engineering management play a certain role in ensuring specific engineering construction process to reduce the probability of accidents so that the engineering construction could be completed as planned.

In the paper, it is elaborated the key trial production plan of 550 MPa grade low alloy high strength steel including the chemical composition, hot rolling, cold rolling and annealing processes in detail as well as studied the effects of alloy elements and production processes on microstructure and properties of products. The trial production results showed that the microstructure of 550 MPa grade low alloy high strength steel was mainly composed of ferrite and dispersed precipitated phase of TiC, its main strengthening mechanisms were fine-grain strengthening and precipitation strengthening as well as its yield strength was 556~581 MPa, tensile strength was 622~653 MPa and elongation was 14.0%~16.5%, which could meet the requirements of relevant standards and product applications.

The composite robot consists of moving chassis with autonomous navigation and robot arm. The moving chassis is with the move function, while robot arm is with the grasping ability. Their mutual integration enables composite robots to perform more complex actions. In this article, it is developed the industrial handling system for composite robot based on the robot operating system (ROS) framework, focused on the problems of handling control and autonomous navigation with tracking for the system as well as explored how to improve its handling efficiency and accuracy. The composite robot could accurately perform handling tasks of workpieces by designing and implementing a reliable strategy of control and autonomous navigation.

In order to achieve effective logistics control for metallurgical waste slag, the intelligent management and control system is realized, in which such transportation and sale processes as contract, plan, clean transportation, weighing, confirmation of loading and unloading in stock ground as well as automatic transportation to outside of plant are integrated through the remote access and control technology, automatic license plate recognition technology with surveillance camera at guard room and development of App on cell phone. As a result, the loopholes in the processes of sales, transportation and measurement for metallurgical waste slag are eliminated as well as the cheating behaviors are completely eradicated so that the levels of measurement control and informatization management for enterprise are improved.

In this paper, the causes for higher burnup are obtained by analyzing the management and operations of heating furnace in detail based on the heat transfer of billet in heating furnace aiming at the phenomenon that the burnup per ton of steel of regenerative heating furnace in 1^# production line of Long Products Plant of Baotou Steel is obviously higher. A series of improvement measures and operation optimizations such as refining and strengthening the thermal management of heating furnace as well as improving hot charging rate, reducing heat losses, controlling exhaust gas temperature and reasonably controlling furnace pressure are put forward based on the working principles and operating features of regenerative heating furnace so that the gas consumption is effectively reduced, production costs are saved and certain economic benefits are obtained.